U.S. patent application number 17/521260 was filed with the patent office on 2022-05-12 for shift device.
This patent application is currently assigned to AISIN CORPORATION. The applicant listed for this patent is AISIN CORPORATION. Invention is credited to Kota ISHIKAWA, Atsuto OGINO, Yutaka UCHIDA.
Application Number | 20220145987 17/521260 |
Document ID | / |
Family ID | |
Filed Date | 2022-05-12 |
United States Patent
Application |
20220145987 |
Kind Code |
A1 |
OGINO; Atsuto ; et
al. |
May 12, 2022 |
SHIFT DEVICE
Abstract
A shift device includes: a shift switching member including
valley portions provided so as to correspond to shift positions; a
positioning member causing the shift position to be established
while being fitted in any of the valley portions of the shift
switching member; a motor driving the shift switching member and
including a rotor and a stator; a driving force transmission
mechanism transmitting a driving force from the motor to the shift
switching member; and a rotor rotation angle sensor and an output
shaft rotation angle sensor detecting rotation angles of the rotor
and the shift switching member. The shift device corrects a
deviation from a center of a preset backlash when a backlash width
included in the driving force transmission mechanism detected based
on output values of the output shaft rotation angle sensor and the
rotor rotation angle sensor is a value or more during a shift
switching operation.
Inventors: |
OGINO; Atsuto; (Kariya-shi,
JP) ; UCHIDA; Yutaka; (Kariya-shi, JP) ;
ISHIKAWA; Kota; (Kariya-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AISIN CORPORATION |
Kariya |
|
JP |
|
|
Assignee: |
AISIN CORPORATION
Kariya
JP
|
Appl. No.: |
17/521260 |
Filed: |
November 8, 2021 |
International
Class: |
F16H 61/32 20060101
F16H061/32; F16H 61/24 20060101 F16H061/24 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 12, 2020 |
JP |
2020-189006 |
Claims
1. A shift device mounted on a vehicle, the shift device
comprising: a shift switching member including a plurality of
valley portions provided so as to correspond to shift positions; a
positioning member configured to cause the shift position to be
established while being fitted in any of the plurality of valley
portions of the shift switching member; a motor configured to drive
the shift switching member and including a rotor and a stator; a
driving force transmission mechanism configured to transmit a
driving force from the motor to the shift switching member; a rotor
rotation angle sensor configured to detect a rotation angle of the
rotor; and an output shaft rotation angle sensor configured to
detect a rotation angle of the shift switching member, wherein the
shift device is configured to correct a deviation from a center of
a preset backlash when a backlash width included in the driving
force transmission mechanism detected based on an output value of
the output shaft rotation angle sensor and an output value of the
rotor rotation angle sensor is equal to or greater than a
predetermined value during a shift switching operation.
2. The shift device according to claim 1, wherein the shift device
is configured to correct the deviation from the center of the
preset backlash based on a deviation between positions of the
valley bottoms of the plurality of valley portions of the shift
switching member and the center of the preset backlash during the
shift switching operation.
3. The shift device according to claim 1, wherein the shift device
is configured to correct the deviation from the center of the
preset backlash based on an increase amount in the backlash width
with respect to an initial backlash width.
4. The shift device according to claim 3, wherein the shift device
is configured to offset the center of the preset backlash by the
increase amount in the backlash width as the deviation from the
center of the preset backlash based on the increase amount in the
backlash width with respect to the initial backlash width.
5. The shift device according to claim 1, wherein the shift device
is configured to obtain the backlash width based on the output
value of the output shaft rotation angle sensor and the output
value of the rotor rotation angle sensor in moving sections in
which the positioning member moves from the valley bottoms of the
valley portions of the shift switching member to top portions of
mountain portions when the shift switching member is rotated in a
first direction and when the shift switching member is rotated in a
second direction opposite to the first direction, and to obtain a
center value of the obtained backlash width as a center of a
corrected new backlash.
6. The shift device according to claim 1, wherein the driving force
transmission mechanism includes a speed reducing mechanism having
the backlash width and is configured to rotate the shift switching
member in a state in which a rotation speed transmitted from the
motor side is reduced, and the shift device is configured to
correct the deviation from the center of the preset backlash when
the backlash width included in the speed reducing mechanism
detected based on the output value of the output shaft rotation
angle sensor and the output value of the rotor rotation angle
sensor is equal to or greater than the predetermined value during
the shift switching operation.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority under 35
U.S.C. .sctn. 119 to Japanese Patent Application 2020-189006, filed
on Nov. 12, 2020, the entire content of which is incorporated
herein by reference.
TECHNICAL FIELD
[0002] This disclosure relates to a shift device, and more
particularly to a shift device including a shift switching member
including a plurality of valley portions.
BACKGROUND DISCUSSION
[0003] In the related art, there has been known a shift device
including a shift switching member including a plurality of valley
portions (see, for example, JP 2005-69406A (Reference 1)).
[0004] The above-mentioned Reference 1 discloses a shift range
switching device including a detent plate including a plurality of
(two) valley portions. The shift range switching device includes a
detent spring, a P-ECU, an actuator, and a shift control mechanism.
The detent plate is a shift switching unit that is driven by the
actuator to switch a shift range. The detent spring is configured
to fix the shift range of the detent plate. The P-ECU is configured
to control an operation of the actuator that drives the shift
control mechanism in order to switch the shift range between a P
range and a non-P range. Here, the P range is a state in which the
detent spring is switched to a valley portion on one side of the
two valley portions of the detent plate. Further, the non-P range
is a state in which the detent spring is switched to the valley
portion on the other side of the two valley portions of the detent
plate.
[0005] The detent plate of the above-mentioned Reference 1 includes
a mountain portion provided between the valley portion on one side
and the valley portion on the other side, a P wall provided on a
side facing the mountain portion side in the valley portion on one
side, and a non-P wall provided on a side facing the mountain
portion side in the valley portion on the other side. Each of the P
wall and the non-P wall is configured to regulate a rotation of the
detent plate by coming into contact with the detent spring.
[0006] The P-ECU of Reference 1 is configured to detect a P wall
position and set the detected P wall position as a reference
position. That is, the P-ECU is configured to perform control for
obtaining the P wall position as a reference position based on the
fact that the detent spring is pressed against the P wall and the
rotation of the detent plate is stopped for a predetermined time.
Accordingly, the P-ECU is configured to perform control for
correcting the P wall position as a preset reference position.
Then, the P-ECU is configured to perform control for correcting a
target rotation position of the actuator where the detent spring
reaches a valley bottom of the valley portion on one side of the
detent plate without the detent spring and the P wall colliding
with each other.
[0007] Further, the P-ECU of the above-mentioned Reference 1 is
configured to detect a non-P wall position and set the detected
non-P wall position as a reference position. That is, the P-ECU is
configured to perform control for obtaining the non-P wall position
as a reference position based on the fact that the detent spring is
pressed against the non-P wall and the rotation of the detent plate
is stopped for a predetermined time. Accordingly, the P-ECU is
configured to perform control for correcting the non-P wall
position as a preset reference position. The P-ECU is configured to
perform control for correcting the target rotation position of the
actuator where the detent spring reaches a valley bottom of the
valley portion on the other side of the detent plate without the
detent spring and the non-P wall colliding with each other.
[0008] In the P-ECU of the above-mentioned Reference 1, when the P
wall position and the non-P wall position deviate due to an
increase in a backlash amount due to wear in the shift device, it
is possible to correct the target rotation position of the actuator
by performing P wall position detection and non-P wall position
detection.
[0009] However, in the shift device of the above-mentioned
Reference 1, it is necessary to press the detent spring against the
P wall for a predetermined time in order to obtain the P wall
position. Further, it is necessary to press the detent spring
against the non-P wall for a predetermined time in order to obtain
the non-P wall position. Accordingly, in the shift device of the
above-mentioned Reference 1, there is a problem that the target
rotation position (rotation angle) of the actuator (motor) that
causes the detent spring (positioning member) to reach the valley
bottoms of the valley portions of the detent plate (shift switching
member) cannot be corrected unless an excessive load is applied to
the detent spring.
[0010] A need thus exists for a shift device which is not
susceptible to the drawback mentioned above.
SUMMARY
[0011] A shift device according to one aspect of this disclosure is
directed to a shift device mounted on a vehicle. The shift device
includes a shift switching member including a plurality of valley
portions provided so as to correspond to shift positions, a
positioning member configured to cause the shift position to be
established while being fitted in any of the plurality of valley
portions of the shift switching member, a motor configured to drive
the shift switching member and including a rotor and a stator, a
driving force transmission mechanism configured to transmit a
driving force from the motor to the shift switching member, a rotor
rotation angle sensor configured to detect a rotation angle of the
rotor, and an output shaft rotation angle sensor configured to
detect a rotation angle of the shift switching member, in which the
shift device is configured to correct a deviation from a center of
a preset backlash when a backlash width included in the driving
force transmission mechanism detected based on an output value of
the output shaft rotation angle sensor and an output value of the
rotor rotation angle sensor is equal to or greater than a
predetermined value during a shift switching operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing and additional features and characteristics of
this disclosure will become more apparent from the following
detailed description considered with the reference to the
accompanying drawings, wherein:
[0013] FIG. 1 is a block diagram showing a control configuration of
a shift device according to an embodiment;
[0014] FIG. 2 is a perspective view schematically showing an
overall configuration of the shift device according to the
embodiment;
[0015] FIG. 3 is a diagram showing a structure of a detent plate
constituting the shift device according to the embodiment;
[0016] FIG. 4 is a cross-sectional view showing an actuator unit
constituting the shift device according to the embodiment;
[0017] FIG. 5 is a diagram showing an internal structure of a speed
reducing mechanism in a state in which a gear housing is removed
from a main body portion in the actuator unit constituting the
shift device according to the embodiment;
[0018] FIG. 6 is a diagram showing an engaged state (driving force
transmittable state) of an intermediate gear in the actuator unit
constituting the shift device according to the embodiment;
[0019] FIG. 7 is a diagram showing an engaged state (driving force
non-transmission state) of the intermediate gear in the actuator
unit constituting the shift device according to the embodiment;
[0020] FIG. 8 is a diagram showing a relationship between an output
value (output voltage) of an output shaft rotation angle sensor, an
output value (motor rotation angle) of a rotor rotation angle
sensor, and a number of rotations of a motor in the shift device
according to the embodiment;
[0021] FIG. 9 is a schematic diagram showing a state when a roller
portion of the shift device according to the embodiment moves from
an R position to an N position;
[0022] FIG. 10 is a schematic diagram showing a state when the
roller portion of the shift device according to the embodiment
moves from the N position to the R position;
[0023] FIG. 11 is a diagram showing a relationship between a first
estimated value, a second estimated value, and a center of backlash
in the shift device according to the embodiment;
[0024] FIG. 12 is an explanatory diagram showing a deviation of the
center of backlash of a driving force transmission mechanism of the
shift device according to the embodiment;
[0025] FIG. 13 is an explanatory diagram showing a movement of a
detent spring when a deviation of the center of backlash is not
corrected in the shift device according to the embodiment;
[0026] FIG. 14 is a diagram showing measurement of a first rotation
angle of the shift device according to the embodiment;
[0027] FIG. 15 is a diagram showing measurement of a current
backlash width of the shift device according to the embodiment;
[0028] FIG. 16 is a diagram showing correction of the center of
backlash of the shift device according to the embodiment; and
[0029] FIG. 17 is a flowchart showing a backlash center position
correction process in the shift device according to the
embodiment.
DETAILED DESCRIPTION
[0030] Hereinafter, embodiments disclosed here will be described
with reference to the drawings.
[0031] A configuration of a shift device 100 will be described with
reference to FIGS. 1 to 16. In the specification of the present
application, "motor rotation angle" and "rotor rotation angle" have
the same meaning.
[0032] The shift device 100 is mounted on a vehicle such as an
automobile. As shown in FIG. 1, when an occupant performs a shift
switching operation via an operation unit such as a shift lever (or
a shift switch), a speed change mechanism 3 is subjected to
electrical shift switching control in the vehicle. That is, a
position of the shift lever is input to the shift device 100 side
via a shift sensor 101 provided in the operation unit. Then, based
on a control signal transmitted from a dedicated ECU 15 provided in
the shift device 100, the speed change mechanism 3 is switched to
any of shift positions of a P (parking) position, an R (reverse)
position, an N (neutral) position, and a D (drive) position
corresponding to a shift operation of the occupant. Such shift
switching control is called shift-by-wire (SBW).
[0033] The shift device 100 includes an actuator unit 1 and a shift
switching mechanism 2 driven by the actuator unit 1. The shift
switching mechanism 2 is mechanically connected to a manual spool
valve (not shown) of a hydraulic valve body in a hydraulic control
circuit unit 3a and a parking mechanism 3b in the speed change
mechanism 3. Further, a shift state (a P position, an R position,
an N position and a D position) of a transmission is mechanically
switched by driving the shift switching mechanism 2.
[0034] The actuator unit 1 includes a motor 11, a rotor rotation
angle sensor 12, an output shaft rotation angle sensor 13, a
driving force transmission mechanism 14, and an electronic control
unit (ECU) 15. As shown in FIG. 2, the ECU 15 is a substrate
component in which electronic components are mounted on a
substrate. Further, these substrate components are housed in a
box-shaped main body portion fixed to a case of the speed change
mechanism 3. Further, the actuator unit 1 includes an output shaft
17 connected to an output side of a speed reducing mechanism
14a.
[0035] As shown in FIG. 2, the shift switching mechanism 2 includes
a detent plate 21 (an example of "shift switching member" in the
claims) and a detent spring 22 (an example of "positioning member"
in the claims). The detent spring 22 is configured to hold the
detent plate 21 at rotation angle positions corresponding to the P
position, the R position, the N position, and the D position,
respectively.
[0036] As shown in FIG. 3, the detent plate 21 has four valley
portions 21a, 21b, 21c, and 21d provided so as to correspond to
shift positions (the P position, the R position, the N position and
the D position). Further, the valley portion 21a, the valley
portion 21b, the valley portion 21c, and the valley portion 21d
form a cam surface Ca having a continuous undulating shape on the
detent plate 21. Further, adjacent valley portions (for example,
the valley portions 21a and 21b, the valley portions 21b and 21c,
and the like) are separated by a mountain portion M having one top
portion T. The detent spring 22 is configured such that a base end
portion thereof (see FIG. 2) is fixed to a casing (see FIG. 2) of
the speed change mechanism 3, and a roller portion 22a is attached
to a free end (see FIG. 2) side thereof. Then, the detent spring 22
is configured such that the roller portion 22a always presses the
cam surface Ca (the position of any of the valley portion 21a, the
valley portion 21b, the valley portion 21c, the valley portion 21d,
and the mountain portions M). Then, the detent spring 22
establishes a shift position while being fitted in any of the
plurality of valley portions 21a, 21 b, 21c, and 21d.
[0037] Further, as shown in FIG. 3, the valley portion 21a arranged
on an outermost end side is provided with a wall portion 121a for
preventing the detent spring 22 from moving beyond the valley
portion 21a. The valley portion 21d arranged on an outermost end
side is provided with a wall portion 121d for preventing the detent
spring 22 from moving beyond the valley portion 21d. Specifically,
the wall portion 121a is provided at the valley portion 21a
arranged at an end portion of the detent plate 21 in a direction of
an arrow A (an example of "first direction" in the claims).
Further, the wall portion 121d is provided at the valley portion
21d arranged at an end portion of the detent plate 21 in a
direction of an arrow B (an example of "second direction" in the
claims).
[0038] Further, as shown in FIG. 2, the detent plate 21 is fixed to
a lower end portion (Z2 side) of the output shaft 17, and the
detent plate 21 is rotated around a rotation axis C1 integrally
with the output shaft 17. Thus, the detent spring 22 is configured
such that the roller portion 22a slides along the cam surface Ca as
the detent plate 21 rotates (swings) forward and reverse in the
direction of the arrow A or the direction of the arrow B, so that
the roller portion 22a is fitted into any of the valley portion
21a, the valley portion 21b, the valley portion 21c and the valley
portion 21d by an urging force of the detent spring 22. Further,
the detent spring 22 is configured such that the roller portion 22a
is selectively fitted into any of the valley portion 21a, the
valley portion 21b, the valley portion 21c and the valley portion
21d of the detent plate 21, so that the detent plate 21 is held at
a rotation angle position corresponding to the P position, the R
position, the N position, or the D position, respectively.
Accordingly, the P position, the R position, the N position or the
D position is individually established.
[0039] Further, as shown in FIG. 1, the shift device 100 includes a
non-volatile storage unit 16. The non-volatile storage unit 16 is
provided inside the actuator unit 1.
[0040] Next, a detailed configuration of the actuator unit 1 will
be described.
[0041] As shown in FIG. 4, the motor 11 includes a rotor 111
rotatably supported with respect to a motor housing and a stator
112 arranged so as to face each other with a magnetic gap around
the rotor 111. Further, the motor 11 is configured to drive the
detent plate 21.
[0042] Further, a surface magnet type (SPM) three-phase motor
having a permanent magnet incorporated in the surface of the rotor
111 is used as the motor 11. Specifically, the rotor 111 has a
shaft pinion 111a and a rotor core 111b.
[0043] The shaft pinion 111a of the rotor 111 and the output shaft
17 are rotated around the same rotation axis C1. Further, in the
shaft pinion 111a, a gear portion 141 having a gear groove formed
in a helical shape is integrally formed in an outer peripheral
region extending from a central portion to the lower end portion
(Z2 side).
[0044] The stator 112 has a stator core 112a fixed in a motor
chamber of the motor housing, and an exciting coil (not shown) of a
plurality of phases (U-phase, V-phase and W-phase) that generates a
magnetic force when energized.
[0045] The rotor rotation angle sensor 12 is configured to detect a
rotation angle of the motor 11. For example, the rotor rotation
angle sensor 12 includes a magneto resistive (MR) sensor.
[0046] The output shaft rotation angle sensor 13 is configured to
detect a rotation angle of the detent plate 21 (output shaft 17).
For example, the output shaft rotation angle sensor 13 includes a
Hall element. In addition, a rotation position (output angle) of
the output shaft 17 is detected as a continuous voltage value.
[0047] As shown in FIGS. 4 and 5, the driving force transmission
mechanism 14 includes the speed reducing mechanism 14a. The speed
reducing mechanism 14a is configured to rotate the detent plate 21
in a state in which a rotation speed transmitted from the motor 11
side is reduced. Specifically, the speed reducing mechanism 14a
includes the gear portion 141 of the rotor 111, an intermediate
gear 142 having a gear portion 142a that meshes with the gear
portion 141, an intermediate gear 143 that is arranged on a lower
surface side (Z2 side) at the same axis as the intermediate gear
142 and engages with the intermediate gear 142, and a final gear
144 having a gear portion 144a that meshes with a gear portion 143a
of the intermediate gear 143.
[0048] Further, as shown in FIGS. 6 and 7, the intermediate gear
142 is formed with a plurality of (six) elongated holes 142b having
a long diameter extending along a circumferential direction between
a rotation center portion and an outer peripheral portion (gear
portion 142a). The plurality of elongated holes 142b are arranged
at intervals of 60 degrees in the circumferential direction.
Further, the intermediate gear 143 has an elliptical main body
portion 143b provided with the gear portion 143a, and is provided
with a plurality of (two) cylindrical engaging convex portions 143c
protruding upward from an upper surface (Z1 side) of the main body
portion 143b opposite to the gear portion 143a. The engaging convex
portions 143c are arranged on peripheral edges on both sides in a
long diameter direction of the main body portion 143b. Then, in a
state in which the intermediate gear 143 is arranged adjacent to
the intermediate gear 142 from the lower side to the upper side (Z1
side), each of the engaging convex portions 143c arranged at an
interval of 180 degrees is inserted (engaged) into each of the two
elongated holes 142b of the corresponding intermediate gear
142.
[0049] In addition, the engaging convex portions 143c is fitted to
the elongated hole 142b of the intermediate gear 142 with a
backlash Ba having a predetermined size (a length in the
circumferential direction). That is, relatively free rotation (free
rotation) between the intermediate gear 142 and the intermediate
gear 143 is allowed by the backlash Ba (predetermined angular
width) in the circumferential direction generated in the engaging
convex portion 143c and the elongated hole 142b that are fitted
into each other. In addition, FIG. 6 shows a state in which a
driving force can be transmitted from the intermediate gear 142 to
the intermediate gear 143, and FIG. 7 shows a state in which the
driving force cannot be transmitted from the intermediate gear 142
to the intermediate gear 143.
[0050] Next, the relationship between a movement of the shift
position and an output value of the output shaft rotation angle
sensor 13 and an output value of the rotor rotation angle sensor 12
will be described.
[0051] As shown in FIG. 8, as the number of rotations of the motor
11 (0 times, 1 time, 2 times, . . . , 7 times) increases, the
detent plate 21 connected to the output shaft 17 rotates so that
the shift position changes in an order of the P position, the R
position, the N position, and the D position. At this time, the
detent spring 22 is fitted into the valley portion 21a, the valley
portion 21b, the valley portion 21c, and the valley portion 21d in
this order. Then, the output value of the output shaft rotation
angle sensor 13 increases as the number of rotations of the motor
11 increases.
[0052] For example, as shown in FIGS. 8 and 9, it is assumed that
the roller portion 22a is currently fitted into the valley portion
21b (R position) (section 1). The motor 11 (see FIG. 1) is driven,
so that the detent plate 21 is rotated in the direction of the
arrow A via the speed reducing mechanism 14a (see FIG. 1). In
addition, a predetermined amount of the backlash Ba (see FIG. 7) is
provided between the intermediate gear 142 and the intermediate
gear 143. Therefore, in a state in which the roller portion 22a is
completely fitted into a valley bottom V of the valley portion 21b,
the engaging convex portion 143c is engaged with the inside of the
elongated hole 142b by utilizing the backlash Ba so as not to able
to transmit the driving force although the intermediate gear 142 is
rotated with a rotation of the rotor 111, and therefore the
intermediate gear 143 is not rotated. As a result, in the section
1, while the rotation angle (rad) of the motor 11 detected by the
rotor rotation angle sensor 12 (see FIG. 1) increases linearly, a
voltage level corresponding to the rotation angle of the output
shaft 17 detected by the output shaft rotation angle sensor 13 (see
FIG. 1) is constant.
[0053] Then, in a section 2, one side end portion of the elongated
hole 142b of the intermediate gear 142 is engaged with the engaging
convex portion 143c of the intermediate gear 143 so that the
driving force can be transmitted, and therefore the driving force
of the motor 11 is transmitted to the output shaft 17 (see FIG. 2)
via the gear portion 141, the intermediate gear 142, the
intermediate gear 143, and the final gear 144 (see FIG. 4). At this
time, the one side end portion of the elongated hole 142b of the
intermediate gear 142 comes into contact with the engaging convex
portion 143c of the intermediate gear 143, so that the one side end
portion of the elongated hole 142b of the intermediate gear 142
wears. Then, as the detent plate 21 rotates in the direction of the
arrow A, the roller portion 22a moves so as to climb a slope of the
valley portion 21b (R position) on the valley portion 21c (N
position) side toward the mountain portion M. In addition, in the
section 2, the rotation angle (rad) of the motor 11 detected by the
rotor rotation angle sensor 12 (see FIG. 1) increases linearly.
Further, the voltage level corresponding to the rotation angle of
the output shaft 17 detected by the output shaft rotation angle
sensor 13 (see FIG. 1) increases at a constant rate.
[0054] Then, in a section 3, after the roller portion 22a climbs
over the mountain portion M at a boundary between the valley
portion 21b (R position) and the valley portion 21c (N position),
the detent plate 21 is rotated ahead of the motor 11 (intermediate
gear 142). That is, the detent plate 21 is always urged toward the
valley portion 21b by the roller portion 22a, and therefore the
detent plate 21 is rotated ahead of the motor 11 within a range of
a size of the backlash Ba of the elongated hole 142b by the urging
force. At this time, the other side end portion of the elongated
hole 142b of the intermediate gear 142 comes into contact with the
engaging convex portion 143c of the intermediate gear 143, so that
the other side end portion of the elongated hole 142b of the
intermediate gear 142 wears. Then, the roller portion 22a is
dropped toward the valley bottom V of the valley portion 21c (see
the section 3 in FIG. 9). At this time, while the rotation angle of
the motor 11 increases, the voltage level corresponding to the
rotation angle of the output shaft 17 sharply increases as the
roller portion 22a drops (is sucked) into the valley bottom V.
[0055] In addition, an operation for a movement of the shift
position from the P position to the R position and a movement from
the N position to the D position are the same as the operation for
the movement from the R position to the N position.
[0056] Further, as shown in FIGS. 8 and 10, when a rotation
direction of the motor 11 is reversed, the shift position is moved
to the R position via the N position (section 4), a section 5, and
a section 6.
[0057] In addition, the operation of the N position (section 4) is
the same as the operation of the section 1. That is, while the
rotation angle (rad) of the motor 11 detected by the rotor rotation
angle sensor 12 (see FIG. 1) decreases linearly, the voltage level
corresponding to the rotation angle of the output shaft 17 detected
by the output shaft rotation angle sensor 13 (see FIG. 1) is
constant.
[0058] Further, the operation of the section 5 is the same as the
operation of the section 2. That is, in the section 5, the rotation
angle of the motor 11 decreases linearly, and the voltage level
corresponding to the rotation angle of the output shaft 17
decreases at a constant rate. At this time, the other side end
portion of the elongated hole 142b of the intermediate gear 142
comes into contact with the engaging convex portion 143c of the
intermediate gear 143, so that the other side end portion of the
elongated hole 142b of the intermediate gear 142 wears.
[0059] Further, the operation of the section 6 is the same as the
operation of the section 3. That is, while the rotation angle of
the motor 11 decreases, the voltage level corresponding to the
rotation angle of the output shaft 17 sharply decreases as the
roller portion 22a drops (is sucked) into the valley bottom V. At
this time, the one side end portion of the elongated hole 142b of
the intermediate gear 142 comes into contact with the engaging
convex portion 143c of the intermediate gear 143, so that the one
side end portion of the elongated hole 142b of the intermediate
gear 142 wears.
[0060] Here, as shown in FIG. 11, in the shift device 100, for
example, at the time of factory shipment, the rotation angle of the
motor 11 (rotor 111) corresponding to the valley bottom V is
obtained (learned) for each shift device 100. The graph shown in
FIG. 11 is a graph showing a relationship between the voltage (V)
and the rotation angle (rad) with the output value (voltage) of the
output shaft rotation angle sensor 13 as a horizontal axis and the
output value (rotation angle) of the rotor rotation angle sensor 12
as a vertical axis. In addition, the vertical axis actually
represents an integrated value of the rotation angle of the motor
11 (that is, 2.pi..times.the number of rotations of the motor
11+the rotation angle).
[0061] The obtaining (learning) of the rotation angle of the motor
11 (rotor 111) corresponding to the valley bottom V (a center Cp of
the backlash Ba) at each of the plurality of shift positions (the P
position, the R position, the N position and the D position) will
be described below. In addition, the rotation angle of the motor 11
corresponding to the valley bottom V is obtained by, for example,
the ECU 15.
[0062] That is, the detent spring 22 (roller portion 22a) is moved
so as to continuously pass through the valley portion 21a, the
valley portion 21b, the valley portion 21c, and the valley portion
21d. Then, a backlash width W included in the speed reducing
mechanism 14a is detected based on the output value of the output
shaft rotation angle sensor 13 and the output value of the rotor
rotation angle sensor 12 while the detent spring 22 is being
moved.
[0063] Specifically, the detent spring 22 is continuously moved in
an order of the P position, the R position, the N position, the D
position, the N position, the R position, and the P position. The
output value of the output shaft rotation angle sensor 13 and the
output value of the rotor rotation angle sensor 12 detected in a
forward path in which the detent spring 22 moves in an order of the
P position, the R position, the N position, and the D position are
represented by thick lines on a straight line L1 in FIG. 11.
Further, the output value of the output shaft rotation angle sensor
13 and the output value of the rotor rotation angle sensor 12
detected in a return path in which the detent spring 22 moves in an
order of the D position, the N position, the R position, and the P
position are represented by thick lines on a straight line L2 in
FIG. 11.
[0064] Then, the ECU 15 detects the backlash width W of the
backlash Ba included in the speed reducing mechanism 14a based on
the output value of the output shaft rotation angle sensor 13 and
the output value of the rotor rotation angle sensor 12 in moving
sections (the section 1, the section 2 and the section 5).
[0065] Here, the moving sections mean sections in which the detent
spring 22 moves through each of the valley bottoms V of the
plurality of valley portions 21a, 21b, 21c, and 21d of the detent
plate 21, and the top portions T of the mountain portions M. In the
moving sections, the backlash Ba between the intermediate gear 142
and the intermediate gear 143 is reduced, and the intermediate gear
143 rotates with the rotation of the intermediate gear 142.
[0066] Further, the backlash width W means a backlash width W (see
FIG. 6) between the engaging convex portion 143c and the elongated
hole 142b in a state in which the backlash Ba is reduced (the state
in which the driving force can be transmitted from the intermediate
gear 142 to the intermediate gear 143).
[0067] The section 2 includes a section 2 when the detent spring 22
moves from the P position to the R position, a section 2 when the
detent spring 22 moves from the R position to the N position, and a
section 2 when the detent spring 22 moves from the N position to
the D position. Further, the section 5 includes a section 5 when
the detent spring 22 moves from the D position to the N position, a
section 5 when the detent spring 22 moves from the N position to
the R position, and a section 5 when the detent spring 22 moves
from the R position to the P position.
[0068] The ECU 15 is configured to perform control for obtaining
the straight line L1 by a linear approximation of the output value
of the rotor rotation angle sensor 12 with respect to the output
value of the output shaft rotation angle sensor 13 in a plurality
of moving sections (three sections 2 and the thick lines on the
straight line L1 in FIG. 11) when the motor 11 is rotated in the
direction of the arrow A. That is, a slope al and an intercept 131
of the straight line L1 are calculated.
[0069] The ECU 15 is configured to perform control for obtaining
the straight line L2 by a linear approximation of the output value
of the rotor rotation angle sensor 12 with respect to the output
value of the output shaft rotation angle sensor 13 in a plurality
of moving sections (three sections 5 and the thick lines on the
straight line L2 in FIG. 11) when the motor 11 is rotated in the
direction of the arrow B. That is, a slope a2 and an intercept b2
of the straight line L2 are calculated.
[0070] The ECU 15 detects a width between the straight line L1
obtained by the linear approximation and the straight line L2
obtained by the linear approximation as the backlash width W. That
is, since a predetermined amount of the backlash Ba is provided in
advance between the intermediate gear 142 and the intermediate gear
143, even the same output value of the output shaft rotation angle
sensor 13 (horizontal axis) causes a difference in the rotation
angle of the motor 11 (vertical axis). Then, this difference can be
regarded as the backlash width W.
[0071] The ECU 15 is configured to perform control for obtaining
the rotation angle of the motor 11 corresponding to the center Cp
of the backlash Ba based on the detected backlash width W.
Specifically, the ECU 15 is configured to perform control for
obtaining a straight line L3 as the center Cp of the backlash Ba
passing through the center between the straight line L1 and the
straight line L2 as the rotation angle of the motor 11
corresponding to the center Cp of the backlash Ba. That is, a slope
(hereinafter, referred to as a3) and an intercept (hereinafter,
referred to as b3) of the straight line L3 are calculated.
[0072] Then, based on the relationship between the rotation angle
of the motor 11 corresponding to the calculated center Cp of the
backlash Ba and the output value of the output shaft rotation angle
sensor 13 corresponding to any of the valley bottoms V of the
valley portion 21a, the valley portion 21b, the valley portion 21c
and the valley portion 21d, the rotation angle of the motor 11
corresponding to the center Cp of the backlash Ba is obtained.
Specifically, the output values of the output shaft rotation angle
sensor 13 in a plurality of sections 1 (sections 1 corresponding to
the P position, the R position, the N position, and the D position)
when the motor 11 is rotated in the direction of the arrow A are
obtained. In addition, the output value of the output shaft
rotation angle sensor 13 in each of the plurality of sections 1 is
a constant value. Specifically, the output values of the output
shaft rotation angle sensor 13 corresponding to the P position, the
R position, the N position, and the D position are an output value
E1, an output value E2, an output value E3, and an output value E4,
respectively.
[0073] Further, the output values of the output shaft rotation
angle sensor 13 in a plurality of sections 4 (sections 4
corresponding to the D position, the N position, the R position,
and the P position) when the motor 11 is rotated in the direction
of the arrow B are obtained. In addition, the output value of the
output shaft rotation angle sensor 13 in each of the plurality of
sections 4 is a constant value. Specifically, the output values of
the output shaft rotation angle sensor 13 corresponding to the D
position, the N position, the R position, and the P position are
the output value E4, the output value E3, the output value E2, and
the output value El, respectively. That is, the output value of the
output shaft rotation angle sensor 13 in the section 1 and the
output value of the output shaft rotation angle sensor 13 in the
section 4 at the same shift position are substantially the
same.
[0074] Then, in the straight line L3, the rotation angle of the
motor 11 corresponding to the section 1 (or the section 4) is
obtained. Specifically, a rotation angle .theta.1, a rotation angle
.theta.2, a rotation angle .theta.3, and a rotation angle .theta.4
of the motor 11 corresponding to the output value E1, the output
value E2, the output value E3, and the output value E4 of the
output shaft rotation angle sensor 13, respectively, are obtained.
As a result, the rotation angle .theta.1, the rotation angle
.theta.2, the rotation angle .theta.3, and the rotation angle
.theta.4 of the motor 11 corresponding to the valley bottoms V (the
center Cp of the backlash Ba) of the P position, the R position,
the N position, and the D position are obtained, respectively.
Here, the rotation angle A1, the rotation angle 92, the rotation
angle .theta.3, and the rotation angle .theta.4 of the motor 11 are
rotation angles of the motor 11 that cause the detent spring 22 to
reach the valley bottom V of the valley portion 21a, the valley
bottom V of the valley portion 21b, the valley bottom V of the
valley portion 21c, and the valley bottom V of the valley portion
21d of the detent plate 21, respectively.
[0075] Then, the slopes (a1, a2 and a3) and the intercepts (b1, b2
and b3) of the straight line L1, the straight line L2, and the
straight line L3, and the output values (E1, E2, E3 and E4) of the
output shaft rotation angle sensor 13 and the rotation angles
(.theta.1, .theta.2, .theta.3, and .theta.4) of the motor 11
corresponding to the valley bottoms V (the centers Cp of backlash
Ba) of the P position, the R position, the N position, and the D
position are stored in the storage unit 16.
(Correction of Valley Bottom Position Corresponding to Shift
Position)
[0076] As shown in FIGS. 12 to 16, the ECU 15 of the present
embodiment is configured to correct a deviation Ga from the center
Cp of a preset backlash Ba when a current backlash width Wp
included in the speed reducing mechanism 14a detected based on the
output value of the output shaft rotation angle sensor 13 and the
output value of the rotor rotation angle sensor 12 is equal to or
greater than a predetermined value during the shift switching
operation. That is, the ECU 15 is configured to perform control for
correcting the deviation Ga between the center Cp of the backlash
Ba corresponding to each valley bottom V of an initial (preset) P
position, R position, N position, and D position and a center Cr of
the backlash Ba corresponding to each valley bottom V of a current
P position, R position, N position, and D position, which is caused
by an increase in the backlash width W (an initial backlash width
Wi) due to wear (aged wear) of at least one of the one side end
portion and the other side end portion of the elongated hole 142b
of the intermediate gear 142.
[0077] Specifically, the ECU 15 is configured to correct the
deviation Ga from the center Cp of the preset backlash Ba when the
current backlash width Wp included in the speed reducing mechanism
14a detected based on the output value of the output shaft rotation
angle sensor 13 and the output value of the rotor rotation angle
sensor 12 is equal to or greater than the predetermined value
during the shift switching operation.
[0078] Hereinafter, an increase of the initial backlash width W
will be described, and for the simplification of description, a
case where only one side end portion of the elongated hole 142b of
the intermediate gear 142 wears will be described as an example.
Actually, the other side end portion of the elongated hole 142b of
the intermediate gear 142 also wears.
[0079] As shown in FIGS. 12 and 13, a width of the elongated hole
142b of the intermediate gear 142 increases due to aged wear caused
by contact of the intermediate gear 143 with the engaging convex
portion 143c. That is, a position of the one side end portion of
the elongated hole 142b of the intermediate gear 142 is set away
from an initial position of the one side end portion of the
elongated hole 142b of the intermediate gear 142. Accordingly, the
current backlash width Wp of the elongated hole 142b of the
intermediate gear 142 is greater than the initial backlash width WI
of the elongated hole 142b of the intermediate gear 142. As a
result, a deviation Ga occurs between the center Cp of the initial
backlash Ba and the center Cr of the backlash Ba after aged wear.
Further, as the initial backlash width WI increases, the following
may occur.
[0080] For example, when switching from the R position to the N
position, the ECU 15 performs control for rotating the rotor 111 by
an amount necessary for the roller portion 22a to move from the
valley portion 21b (the R position) toward the valley portion 21c
(the N position). Here, in the section 3, the rotor 111 rotates to
a position where the roller portion 22a climbs over the mountain
portion M at the boundary between the valley portion 21b (the R
position) and the valley portion 21c (the N position); however, due
to the increase in the backlash width W, the roller portion 22a may
not actually move to the position where the roller portion 22a
climbs over the mountain portion M at the boundary between the
valley portion 21b (the R position) and the valley portion 21c (the
N position).
[0081] In this case, the roller portion 22a stops in the middle of
the valley portion 21c without dropping into the valley bottom V of
the valley portion 21b. As a result, the output shaft 17 cannot be
moved to the valley bottom V, so that an accuracy of position
control of the shift position is lowered.
[0082] Therefore, the ECU 15 is configured to correct the deviation
Ga from the center Cp of the preset backlash Ba based on a
deviation Ga between the position of the valley bottom V of the
valley portion 21b of a shift switching member and the center Cp of
the preset backlash Ba during the shift switching operation. That
is, the ECU 15 is configured to perform control for measuring an
increase amount Am of the backlash width W due to the increase of
the backlash width W, and offsetting the position of the center Cp
of the backlash Ba corresponding to the valley bottom V of each of
the initial P position, R position, N position, and D position by
the increase amount Am.
[0083] As an example, a measurement of the increase amount Am of
the backlash width W at the R position will be described with
reference to FIGS. 14 to 16. Further, in this example, for the
simplification of description, it is assumed that only one side end
portion of the elongated hole 142b of the intermediate gear 142
wears. In addition, the increase amount Am of the backlash width W
can be measured not only at the R position but also at the P
position, the N position, and the D position by the same
method.
[0084] As shown in FIG. 14, the ECU 15 is configured to perform
control for obtaining a first rotation angle .theta.a that is a
rotation angle of the motor 11 at the R position (a predetermined
shift position) when the detent plate 21 is rotated in the A
direction. Here, the predetermined shift position indicates a shift
position when the first rotation angle .theta.a is obtained.
[0085] Then, the ECU 15 is configured to perform control for
determining whether a difference Di between an initial rotation
angle .theta.2 of the rotor 111 measured by the rotor rotation
angle sensor 12 corresponding to the valley bottom V of the valley
portion 21b at the R position when the detent plate 21 is rotated
in the A direction and the first rotation angle .theta.a is equal
to or greater than a threshold value. The ECU 15 is configured to
perform control for storing the first rotation angle .theta.a in
the storage unit 16 based on the difference Di between the initial
rotation angle .theta.2 of the rotor 111 and the first rotation
angle .theta.a being equal to or greater than the threshold value.
Further, the ECU 15 is configured to perform control for storing in
the storage unit 16 that the difference Di between the initial
rotation angle .theta.2 of the rotor 111 and the first rotation
angle .theta.a is equal to or greater than the threshold value.
[0086] As shown in FIG. 15, the ECU 15 is configured to perform
control for obtaining the current backlash width Wp based on the
output values of the output shaft rotation angle sensor 13 and the
output values of the rotor rotation angle sensor 12 in the moving
sections in which the detent spring 22 moves from the valley bottom
V of the valley portion 21b of the shift switching member to the
top portion T of the mountain portion M when the detent plate 21 is
rotated in the A direction and when the detent plate 21 is rotated
in the B direction opposite to the A direction.
[0087] Specifically, the ECU 15 is configured to perform control
for obtaining a second rotation angle .theta.b that is a rotor
rotation angle at the R position (the predetermined shift position)
in the case where the difference between the initial rotation angle
A2 of the rotor 111 and the first rotation angle .theta.a is equal
to or greater than the threshold value when the detent plate 21 is
rotated in the B direction.
[0088] Further, the ECU 15 is configured to perform control for
obtaining the current backlash width Wp based on a difference
between the first rotation angle .theta.a and the second rotation
angle .theta.b. That is, the ECU 15 is configured to perform
control for obtaining the current backlash width Wp based on the
difference between the first rotation angle .theta.a of the rotor
111 measured by the rotor rotation angle sensor 12 corresponding to
the valley bottom V of the valley portion 21b at the R position
(the predetermined shift position) when the detent plate 21 is
rotated in the A direction and the second rotation angle .theta.b
of the rotor 111 measured by the rotor rotation angle sensor 12
corresponding to the valley bottom V of the valley portion 21b at
the R position (the predetermined shift position) when the shift
switching member is rotated in the B direction.
[0089] The ECU 15 is configured to perform control for correcting
the straight line L3 stored in the storage unit 16 based on the
current backlash width Wp being equal to or greater than the
predetermined value. That is, the ECU 15 is configured to perform
control for obtaining the increase amount Am of the backlash width
W based on a difference between the initial backlash width Wi and
the current backlash width Wp. Here, the ECU 15 is configured to
perform control for obtaining the initial backlash width Wi at the
R position based on the straight line L1, the straight line L2, and
the output value E2 of the output shaft rotation angle sensor 13
stored in the storage unit 16.
[0090] As shown in FIG. 16, the ECU 15 is configured to correct the
deviation Ga from the center Cp of the preset backlash Ba based on
the increase amount Am of the current backlash width Wp with
respect to the initial backlash width Wi. That is, the ECU 15 is
configured to correct the deviation Ga from the center Cp of the
preset backlash Ba based on the increase amount Am of the current
backlash width Wp with respect to the initial backlash width Wi.
Specifically, the ECU 15 is configured to offset the center Cp of
the preset backlash Ba by the increase amount Am of the current
backlash width Wp as the deviation Ga from the center Cp of the
preset backlash Ba based on the increase amount Am of the current
backlash width Wp with respect to the initial backlash width Wi. In
this case, the rotation angle .theta.2 of the motor 11
corresponding to the center Cp of the preset backlash Ba becomes
smaller by the increase amount Am of the current backlash width Wp.
Then, the ECU 15 is configured to perform control for obtaining a
center value of the current backlash width Wp obtained by
offsetting by the increase amount Am as the center Cr of a
corrected new backlash Ba.
[0091] That is, the ECU 15 is configured to perform control for
correcting the straight line L3 based on the increase amount Am of
the current backlash width Wp. Specifically, the ECU 15 is
configured to perform control for offsetting the intercept b3 of
the straight line L3 while maintaining the slope a3 of the straight
line L3 by the increase amount Am of the current backlash width Wp.
In this case, the value of the intercept b3 of the straight line L3
becomes smaller. Accordingly, the straight line L3 moves by the
increase amount Am of the current backlash width Wp.
[0092] As described above, the ECU 15 is configured to obtain the
current backlash width Wp based on the difference between the first
rotation angle .theta.a and the second rotation angle .theta.b when
the difference Di between the initial rotation angle .theta.2 of
the rotor 111 measured by the rotor rotation angle sensor 12
corresponding to the valley bottom V of the valley portion 21b at
the predetermined shift position when the detent plate 21 is
rotated in the A direction and the first rotation angle .theta.a is
equal to or greater than the threshold value, and to obtain a
center value of the obtained current backlash width Wp as the
center Cr of a corrected new backlash Ba.
[0093] The control for correcting the center value of the initial
backlash width Wi is performed every time a shift position
switching operation is performed. That is, the ECU 15 is configured
to obtain the current backlash width Wp based on the output value
of the output shaft rotation angle sensor 13 and the output value
of the rotor rotation angle sensor 12 each time a shift switching
operation is performed, and to correct the deviation Ga from the
center Cp of the preset backlash Ba when the current backlash width
Wp is equal to or greater than the predetermined value.
(Backlash Center Position Correction Process)
[0094] Hereinafter, a backlash center position correction process
by the ECU 15 will be described with reference to FIG. 17. The
backlash center position correction process is a process of
correcting a center position of the backlash Ba to an appropriate
position in accordance with an increase in the backlash width
W.
[0095] In step S1, the ECU 15 determines whether the shift position
is switched by rotating the detent plate 21 in either the A
direction or the B direction. That is, the ECU 15 determines
whether the shift position is switched to any of the predetermined
shift positions of the P position, the R position, the N position,
and the D position. If the shift position is switched, the process
proceeds to step S2, and if the shift position is not switched,
step S1 is repeated.
[0096] In step S2, the ECU 15 obtains the first rotation angle
.theta.a of the rotor 111 at any of the predetermined shift
position. In step S3, the ECU 15 obtains the difference Di between
the obtained first rotation angle .theta.a and any of the initial
rotation angle .theta.1, the initial rotation angle .theta.2, the
initial rotation angle .theta.3, and the initial rotation angle
.theta.4 corresponding to the predetermined shift positions. In
step S4, the ECU 15 determines whether the difference Di is equal
to or greater than a threshold value. If the difference Di is equal
to or greater than the threshold value, the process proceeds to
step S5, and if the difference Di is less than the threshold value,
the process returns to step S1.
[0097] In step S5, the ECU 15 stores the first rotation angle
.theta.a in the storage unit 16 and also stores that the difference
Di at any of the predetermined shift positions is equal to or
greater than the threshold value. In step S6, the ECU 15 determines
whether the shift position is switched to any of the predetermined
shift positions by rotating the detent plate 21 in a direction
opposite to the rotation direction in step S1. Then, if the shift
position is switched to any of the predetermined shift positions,
the process proceeds to step S7, and if the shift position is not
switched to any of the predetermined shift positions, repeat step
S6 is repeated.
[0098] In step S7, the ECU 15 obtains the second rotation angle
.theta.b as the rotation angle of the rotor 111 at any of the
predetermined shift positions. In step S8, the ECU 15 obtains the
current backlash width Wp based on the difference between the first
rotation angle .theta.a and the second rotation angle .theta.b. In
step S9, the ECU 15 obtains the increase amount Am of the current
backlash width Wp based on the difference between the initial
backlash width Wi and the current backlash width Wp. In step S10,
the ECU 15 offsets the center Cp of the backlash Ba by the increase
amount Am of the current backlash width Wp. That is, in the ECU 15,
the intercept b3 of the straight line L3 is offset by the increase
amount Am of the current backlash width Wp. Then, after step S10,
the backlash center position correction process is completed.
(Effect of Present Embodiment)
[0099] In the present embodiment, the following effect can be
obtained.
[0100] In the present embodiment, as described above, the shift
device 100 is provided with the detent plate 21 including the
valley portion 21a, the valley portion 21b, the valley portion 21c,
and the valley portion 21d provided so as to correspond to the
shift positions, and the detent spring 22 for establishing a shift
position while being fitted into any one of the plurality of valley
portions 21a, 21b, 21c, and 21d of the detent plate 21. The ECU 15
is configured to correct the deviation Ga from the center Cp of a
preset backlash Ba when the current backlash width Wp included in
the driving force transmission mechanism 14 detected based on the
output value of the output shaft rotation angle sensor 13 and the
output value of the rotor rotation angle sensor 12 is equal to or
greater than the predetermined value during the shift switching
operation. Accordingly, by correcting the deviation Ga from the
center Cp of the preset backlash Ba, the positions of the center Cp
of the backlash Ba corresponding to the positions of the valley
bottoms V of the valley portion 21a, the valley portion 21b, the
valley portion 21c, and the valley portion 21d of the detent plate
21 can be corrected without pressing the detent spring 22 against a
wall of the detent plate 21, so that the rotation angle of the
motor 11 corresponding to the position of the center Cr of the
corrected backlash Ba can be obtained. As a result, it is possible
to correct the rotation angle of the motor 11 that causes the
detent spring 22 to reach the valley bottoms V of the valley
portion 21a, the valley portion 21b, the valley portion 21c, and
the valley portion 21d of the detent plate 21 without applying an
excessive load to the detent spring 22. Further, during the shift
switching operation, by correcting the deviation from the center Cp
of the preset backlash Ba, the center Cp of the preset backlash Ba
can be corrected in accordance with the center Cr of the backlash
Ba caused by a backlash width Wr included in the driving force
transmission mechanism 14 that increases due to aged wear, so that
a state in which the center Cr of the backlash Ba matches with the
positions of the valley bottoms V of the plurality of valley
portions 21a, 21b, 21c, and 21d of the detent plate 21 can be
maintained. As a result, it is possible to prevent a decrease in
the accuracy of the position control of the detent spring 22 during
the shift switching operation.
[0101] Further, in the present embodiment, as described above, the
ECU 15 is configured to correct the deviation Ga from the center Cp
of the preset backlash Ba based on the deviation Ga between the
position of the valley bottom V of any one of the valley portion
21a, the valley portion 21b, the valley portion 21c, and the valley
portion 21d of the detent plate 21 and the center Cp of the preset
backlash Ba during the shift switching operation. Accordingly, by
correcting the deviation Ga from the center Cp of the preset
backlash Ba, the center Cr of the backlash Ba can be accurately
matched with the positions of the valley bottoms V of the plurality
of valley portions 21a, 21b, 21c, and 21d of the detent plate 21,
so that the position control of the detent spring 22 during the
shift switching operation can be accurately performed and a
decrease in a determination accuracy of the shift position can be
prevented.
[0102] Further, in the present embodiment, as described above, the
ECU 15 is configured to correct the deviation Ga from the center Cp
of the preset backlash Ba based on the increase amount Am of the
current backlash width Wp with respect to the initial backlash
width Wi. Accordingly, the deviation Ga caused by the increase in
the backlash width W due to wear of the backlash Ba of the driving
force transmission mechanism 14 can be corrected, so that the state
in which the center Cr of the backlash Ba matches with the
positions of the valley bottoms V of the valley portion 21a, the
valley portion 21b, the valley portion 21c, and the valley portion
21d of the detent plate 21 can be maintained. As a result, it is
possible to prevent a decrease in the accuracy of the position
control of the detent spring 22 during the shift switching
operation.
[0103] Further, in the present embodiment, as described above, the
ECU 15 is configured to offset the center Cp of the preset backlash
Ba by the increase amount Am of the backlash width W as the
deviation Ga from the center Cp of the preset backlash Ba based on
the increase amount Am of the current backlash width Wp with
respect to the initial backlash width Wi. Accordingly, by
offsetting the center Cp of the preset backlash Ba in accordance
with the increase amount Am of the current backlash width Wp caused
by wear of the backlash Ba of the driving force transmission
mechanism 14, the deviation Ga between the center Cp of the preset
backlash Ba and the positions of the valley bottoms V of the valley
portion 21a, the valley portion 21b, the valley portion 21c, and
the valley portion 21d of the detent plate 21 can be compensated.
As a result, the state in which the center Cr of the backlash Ba
matches with the positions of the valley bottoms V of the valley
portion 21a, the valley portion 21b, the valley portion 21c, and
the valley portion 21d of the detent plate 21 can be maintained, so
that a decrease in the accuracy of the position control of the
detent spring 22 during the shift switching operation can be
prevented.
[0104] Further, in the present embodiment, as described above, the
ECU 15 is configured to obtain the current backlash width Wp based
on the output value of the output shaft rotation angle sensor 13
and the output value of the rotor rotation angle sensor 12 in the
moving sections in which the detent spring 22 moves from the valley
bottom V of any of the valley portion 21a, the valley portion 21b,
the valley portion 21c, and the valley portion 21d of the detent
plate 21 to the top portion T of the mountain portion M when the
detent plate 21 is rotated in the A direction and when the detent
plate 21 is rotated in the B direction opposite to the A direction,
and to obtain a center value of the obtained current backlash width
Wp as the center Cr of a corrected new backlash Ba. Accordingly, a
new center Cr of the backlash Ba can be obtained based on the
output value of the output shaft rotation angle sensor 13 and the
output value of the rotor rotation angle sensor 12 without
estimating the current backlash width Wp using a linear
approximation or the like, so that the new center Cr of the
backlash Ba can be easily obtained.
[0105] Further, in the present embodiment, as described above, the
driving force transmission mechanism 14 is provided with the speed
reducing mechanism 14a that rotates the detent plate 21 in a state
in which the rotation speed transmitted from the motor 11 side is
reduced and includes the backlash width W. The ECU 15 is configured
to correct the deviation Ga from the center Cp of the preset
backlash Ba when the current backlash width Wp included in the
speed reducing mechanism 14a detected based on the output value of
the output shaft rotation angle sensor 13 and the output value of
the rotor rotation angle sensor 12 is equal to or greater than the
predetermined value during the shift switching operation.
Accordingly, by correcting at least the deviation Ga from the
center Cp of the preset backlash Ba caused by the current backlash
width Wp included in the speed reducing mechanism 14a, the center
Cr of the backlash Ba can be accurately matched with the positions
of the valley bottoms V of the valley portion 21a, the valley
portion 21b, the valley portion 21c, and the valley portion 21d of
the detent plate 21, so that the position control of the detent
spring 22 can be accurately performed during the shift switching
operation.
[Modification]
[0106] It should be considered that the above-mentioned embodiments
disclosed here are examples in all respects and are not
restrictive. The scope of this disclosure is shown by the claims
rather than the description of the above-mentioned embodiments and
further includes all changes (modifications) within the scope and
meaning equivalent to the claims.
[0107] For example, in the above-mentioned embodiments, an example
in which the control for correcting the center value of the
backlash width W is performed for each shift position switching
operation has been shown, but this disclosure is not limited to
this. In this disclosure, control for correcting the center value
of the backlash width may be performed periodically not for each
shift position switching operation but for each predetermined
number of times of switching.
[0108] Further, in the above-mentioned embodiments, an example in
which the backlash width W is the backlash width W of the speed
reducing mechanism 14a has been shown, but this disclosure is not
limited to this. In this disclosure, the backlash width may include
a backlash width other than the speed reducing mechanism in the
driving force transmission mechanism.
[0109] Further, in the above-mentioned embodiments, an example in
which there are four shift positions (P, R, N and D) has been
shown, but this disclosure is not limited to this. In this
disclosure, for example, the disclosure may be applied to a shift
device having the number of shift positions other than four.
[0110] Further, in the above-mentioned embodiments, an example in
which the shift device 100 disclosed here is applied to the shift
device 100 for a vehicle has been shown, but this disclosure is not
limited to this. In this disclosure, the shift device may be
applied to a shift device other than that for a vehicle, for
example, a train.
[0111] Further, in the above-mentioned embodiments, an example in
which the ECU 15 is configured to correct the deviation Ga from the
center Cp of the preset backlash Ba when the current backlash width
Wp is equal to or greater than the predetermined value has been
shown, but this disclosure is not limited to this. In this
disclosure, the ECU may be configured to correct the deviation from
the center of a preset backlash when the increase amount in the
current backlash width is equal to or greater than a specified
value.
[0112] Further, in the above-mentioned embodiments, for the
convenience of explanation, an example in which a control process
of the ECU 15 is described by using a flow-driven flowchart for
sequentially carrying out a process according to a processing flow
has been shown, but this disclosure is not limited to this. In this
disclosure, the control process of the ECU may be carried out by an
event-driven type process for executing a process in event units.
In this case, the process may be carried out in a completely
event-driven manner, or may be carried out by combining
event-driven and flow-driven.
[0113] The principles, preferred embodiment and mode of operation
of the present invention have been described in the foregoing
specification. However, the invention which is intended to be
protected is not to be construed as limited to the particular
embodiments disclosed. Further, the embodiments described herein
are to be regarded as illustrative rather than restrictive.
Variations and changes may be made by others, and equivalents
employed, without departing from the spirit of the present
invention. Accordingly, it is expressly intended that all such
variations, changes and equivalents which fall within the spirit
and scope of the present invention as defined in the claims, be
embraced thereby.
[0114] A shift device according to one aspect of this disclosure is
directed to a shift device mounted on a vehicle. The shift device
includes a shift switching member including a plurality of valley
portions provided so as to correspond to shift positions, a
positioning member configured to cause the shift position to be
established while being fitted in any of the plurality of valley
portions of the shift switching member, a motor configured to drive
the shift switching member and including a rotor and a stator, a
driving force transmission mechanism configured to transmit a
driving force from the motor to the shift switching member, a rotor
rotation angle sensor configured to detect a rotation angle of the
rotor, and an output shaft rotation angle sensor configured to
detect a rotation angle of the shift switching member, in which the
shift device is configured to correct a deviation from a center of
a preset backlash when a backlash width included in the driving
force transmission mechanism detected based on an output value of
the output shaft rotation angle sensor and an output value of the
rotor rotation angle sensor is equal to or greater than a
predetermined value during a shift switching operation.
[0115] As described above, the shift device according to one aspect
of this disclosure is provided with the shift switching member
including the plurality of valley portions provided so as to
correspond to the shift positions and a positioning member for
establishing the shift position while being fitted in any of the
plurality of valley portions of the shift switching member. The
shift device is configured to correct the deviation from the center
of the preset backlash when the backlash width included in the
driving force transmission mechanism detected based on the output
value of the output shaft rotation angle sensor and the output
value of the rotor rotation angle sensor is equal to or greater
than the predetermined value during the shift switching operation.
Accordingly, by correcting the deviation from the center of the
preset backlash, positions of the center of the backlash
corresponding to the positions of the valley bottoms of the
plurality of valley portions of the shift switching member can be
corrected without pressing the positioning member against the wall
of the shift switching member, so that rotation angles of the motor
corresponding to the positions of the center of the corrected
backlash can be obtained. As a result, it is possible to correct
the rotation angle of the motor that causes the positioning member
to reach the valley bottoms of the valley portions of the shift
switching member without applying an excessive load to the
positioning member. In addition, during the shift switching
operation, by correcting the deviation from the center of the
preset backlash, the center of the preset backlash can be corrected
in accordance with the center of a backlash caused by the backlash
width included in the driving force transmission mechanism that
increases due to aged wear, so that a state in which the center of
the backlash matches with the positions of the valley bottoms of
the plurality of valley portions of the shift switching member can
be maintained. As a result, it is possible to prevent a decrease in
an accuracy of position control of the positioning member during
the shift switching operation.
[0116] It is preferable that the shift device according to the
above-mentioned one aspect is configured to correct the deviation
from the center of the preset backlash based on a deviation between
positions of the valley bottoms of the plurality of valley portions
of the shift switching member and the center of the preset backlash
during the shift switching operation.
[0117] With such a configuration, by correcting a deviation from
the center of the preset backlash, the center of the backlash can
be accurately matched with the positions of the valley bottoms of
the plurality of valley portions of the shift switching member, so
that the position control of the positioning member during the
shift switching operation can be accurately performed and a
decrease in a determination accuracy of the shift position can be
prevented.
[0118] It is preferable that the shift device according to the
above-mentioned one aspect is configured to correct the deviation
from the center of the preset backlash based on an increase amount
in the backlash width with respect to an initial backlash
width.
[0119] With such a configuration, the deviation of the center of
the backlash caused by an increase in the backlash width due to
wear of the backlash of the driving force transmission mechanism
can be corrected, so that the state in which the center of the
backlash matches with the positions of the valley bottoms of the
plurality of valley portions of the shift switching member can be
maintained. As a result, it is possible to prevent a decrease in
the accuracy of the position control of the positioning member
during the shift switching operation.
[0120] In this case, it is preferable that the shift device is
configured to offset the center of the preset backlash by the
increase amount in the backlash width as the deviation from the
center of the preset backlash based on the increase amount in the
backlash width with respect to the initial backlash width.
[0121] With such a configuration, by offsetting the center of the
preset backlash in accordance with the increase amount in the
backlash width due to the wear of the backlash of the driving force
transmission mechanism, the deviation between the center of the
preset backlash and the positions of the valley bottoms of the
plurality of valley portions of the shift switching member can be
compensated. As a result, the state in which the center of the
backlash matches with the positions of the valley bottoms of the
plurality of valley portions of the shift switching member can be
maintained, so that a decrease in the accuracy of the position
control of the positioning member during the shift switching
operation can be prevented.
[0122] It is preferable that the shift device according to the
above-mentioned one aspect is configured to obtain the backlash
width based on the output value of the output shaft rotation angle
sensor and the output value of the rotor rotation angle sensor in
moving sections in which the positioning member moves from the
valley bottoms of the valley portions of the shift switching member
to top portions of mountain portions when the shift switching
member is rotated in a first direction and when the shift switching
member is rotated in a second direction opposite to the first
direction, and to obtain a center value of the obtained backlash
width as a center of a corrected new backlash.
[0123] With such a configuration, a new center of backlash can be
obtained based on the output value of the output shaft rotation
angle sensor and the output value of the rotor rotation angle
sensor without estimating the backlash width using linear
approximation or the like, so that a new center of backlash can be
easily obtained.
[0124] It is preferable that, in the shift device according to the
above-mentioned one aspect, the driving force transmission
mechanism includes a speed reducing mechanism having the backlash
width and is configured to rotate the shift switching member in a
state in which a rotation speed transmitted from the motor side is
reduced, and the shift device is configured to correct the
deviation from the center of the preset backlash when the backlash
width included in the speed reducing mechanism detected based on
the output value of the output shaft rotation angle sensor and the
output value of the rotor rotation angle sensor is equal to or
greater than the predetermined value during the shift switching
operation.
[0125] With such a configuration, by correcting at least the
deviation from the center of the preset backlash caused by the
backlash width included in the speed reducing mechanism, the center
of the backlash can be accurately matched with the positions of the
valley bottoms of the plurality of valley portions of the shift
switching member, so that the position control of the positioning
member can be accurately performed during the shift switching
operation.
[0126] In addition, the following configurations are also possible
in the shift device according to the above-mentioned one
aspect.
(Appendix 1)
[0127] That is, the shift device including the shift switching
member that rotates in the first direction and the second direction
is configured to obtain the backlash width based on a difference
between a first rotation angle of the rotor measured by the rotor
rotation angle sensor corresponding to a valley bottom of a valley
portion at predetermined shift position when the shift switching
member is rotated in the first direction and a second rotation
angle of the rotor measured by the rotor rotation angle sensor
corresponding to a valley bottom of a valley portion at a
predetermined shift position when the shift switching member is
rotated in the second direction, and to obtain a center value of
the obtained backlash width as a center of a corrected new
backlash.
[0128] With such a configuration, the backlash width can be
obtained more accurately by obtaining the backlash width using both
the first rotation angle and the second rotation angle, so that a
new center of backlash can be obtained more accurately.
(Appendix 2)
[0129] In this case, the shift device is configured to, when a
difference between an initial rotation angle of the rotor measured
by the rotor rotation angle sensor corresponding to a valley bottom
of a valley portion at a predetermined shift position when the
shift switching member is rotated in the first direction and the
first rotation angle is greater than or equal to a threshold value,
obtain a backlash width based on the difference between the first
rotation angle and the second rotation angle, and obtain a center
value of the obtained backlash width as a center of a corrected new
backlash.
[0130] With such a configuration, by obtaining the backlash width
when the difference between the initial rotation angle and the
first rotation angle is equal to or greater than the threshold
value, a process of obtaining the backlash width can be efficiently
performed, and a control load of the process of obtaining the
backlash width can be reduced, compared with a case where the
backlash width is always obtained.
(Appendix 3)
[0131] The shift device according to the above-mentioned one aspect
is configured to obtain the backlash width based on the output
value of the output shaft rotation angle sensor and the output
value of the rotor rotation angle sensor each time the shift
switching operation is performed, and to correct the deviation from
the center of the preset backlash when the backlash width is equal
to or greater than the predetermined value.
[0132] With such a configuration, an increase in the backlash width
of the driving force transmission mechanism due to wear can be
detected at an early stage, so that the deviation between the
center of the backlash and the positions of the valley bottoms of
the plurality of valley portions of the shift switching member can
be corrected at an early stage.
* * * * *